Double-cutting band-saw mill.



PATENTED JAN. a, 1903.

-H. G. DITTBENNER.

DOUBLE CUTTING BAND SAW MILL. APPLICATION FILED JULY 12, 1902.

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' N0. 717,733. PAT-ENTED' JAN. 6, 1903.

H. G. DITTBENNER. DOUBLE GUTTINGBAND SAWMILL.

APPLICATION FILED JULY 12, 1902.

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- PATENTED JAN. 6, 1903.

- H. G. DITTBBNNER.

DOUBLE CUTTING BAND SAW MILL.

APPLIGATION FILED JULY 12! 1902.

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' the novel devices and combinations of devices UNITED STATES PATENT OFFICE.

HERMANN G. DITTBENNER, OF MINNEAPOLIS, MINNESOTA.

DOUBLE-CUTTING BAND-SAW MILL.

SPECIFICATION forming part of Letters IPatent No. 717,738, dated January 6, 1903.

Application filed July 12, 1902. Serial No. 115,368. (No model.)

NEE, a citizen of the United States, residing at Minneapolis, in' the county .of Hennepin and State of Minnesota,have invented certain new and useful Improvements in Double-Cutting Band-Saw Mills; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to band-saw mills, and

has for its object to provide certain improved devices for use in connection therewith.

More specifically stated, the especial objects of my invention are to provide, first, improved bridging devices for bridging over the space between the log-deck-aud the carriage without interrupting or interfering with the actions of the lumber-conveyor or conveying means, and, second, to provide an improved lumber-conveying device. Both of the said devices are particularly adapted for use in connection with what is known as a doublecutting band-saw mill to wit, a sawmill which will out under both directions of move ment of the log-carriage.

To the above ends the invention consists of hereinafter described, and defined in the claims.

The invention is illustrated in the accompanying drawings, wherein like characters indicate like parts throughout the several views.

Figure 1 is a plan view with some parts broken away and others removed, showing a double-cutting band-saw mill embodying the several features of my invention. Fig. 2 is a vertical section taken approximately on the line 00 m of Fig. 1, some parts being-broken away. Fig. 3 is a detail view in plan, with parts broken away, showing the bridging devices ancl means for actuating the same; and Fig. 4 is a skeleton view, in side elevation, showing the chain-conveying belts and driving connections therefor.

The numeral 1 indicates the floor of a mill, the numeral 2 a carriage-track, the numeral 3 the log-carriage movable on said track, and the numeral 4 the log-deck.

The numeral 5 indicates the double-cutting said roller in Fig. l.

band-saw, and the numeral 6 indicates live rollers, which rollers constitute part of the lumber-conveying mechanism and are so located that they feed the lumber through the loop of the band-saw 5.

The above parts are of ordinary or standard construction.

The character 2 indicates a log. (Shown by full lines on the deck 4 and by dotted lines on the carriage 3.) As will of course be understood, the log on the carriage is moved first in one direction and then in the other past the saw 5, and a board is out under each movement of said carriage. A board cut from the log when the carriage is moved toward the observer of Fig. 1 will fall under the live roller 6 and be carried in the direction indicated by the arrow marked in connection with A board cut from the log under a reverse movement of the carriage will fall onto conveying devices, which constitute one feature of mypresent invention and which will presently be described.

The lower end of the log-deck 4 is spaced apart laterally from the adjacent side of the track 2 and adjacent edge of the carriage 3, and, as shown, it rests on its lower edge on a heavy beam '7, which runs parallel to the track 2 and parallel to a laterally-spaced beam 8, which is rigidly supported just outward of but above the adjacent rail of said track by means of a depressed or lower decksection 9. The lower end of the log-deck 4 terminates approximately on a level with the platform of the log-carriage 3.

side of the nigger 10 is an endless lumber-conveyer or conveying-belt, made up of a plurality of parallel and closely-positioned sprocketchains 11, which run over sprocket-wheels 12, secured in series on short transverse shafts 13, suitably mounted on the beams 7 and 8 or parts supported therefrom. The forward shafts 13 of each conveyer 11 are also provided with sprockets 14, over which run suitably-driven sprocket-chains 15, which impart the required movements to the said conveyors.

A pair of bridging-arms 16 are pivoted to the timber '7 just below the delivery end of the deck 4:. The pivoted ends of these arms 16 are protected by guard-plates 17, rigidly secured to the deck 4, as bestshown in Fig. 2. The bridging-arms 16 are thus mounted for oscillating movements in a horizontal plane, and their free ends are adapted to be thrown ata right angle to the track 2 on a level with and in close proximity to the platform or head-blocks of the log-carriage, as shown in the drawings. When the arms 16 are thus projected or turned, they form a continuation, as it were, of the delivery end of the logdeck, and as they stand a considerable distance above the tops of the conveying-belts 11 they permit the same to continue their action of moving forward the board which was cut from the log under the movement of the log-carriage in a direction away from the observer of Fig. 1. When the said arms 16 stand in their operative positions, as shown, their free ends rest upon bearing-lugs 18 on the top of the beam 8. As shown, cam plates or surfaces 19 incline outward and downward from the rest-lugs 18 and serve to insure the upward movements of the free ends of said arms for proper engagement with the restlugs 18 in case the said arms should be pressed downward by the log or for other cause while they are being moved into their operative positions. At their pivoted or outer endslhe arms 16 are provided with short extensions 20, which are connected by a link 21. One of the arm extensions 20 or one end of the link 21 is connected by a pitman or rod 22 to the piston-rod 23 of a small fluid-pressure motor 24, which, as shown, is supported by the beam 7, but which may be supported in any suitable way. The said fluid-pressure motor or engine 24: may of course be controlled in any suitable way. In Figs. 1 and 3 the piston-rod 23 is shown as projected to its extreme position. It is of course evident that when the piston-rod 23 is drawn inward or into the cylinder of the motor 24 the two bridgingarms 16 will be oscillated into the positions indicated by dotted lines in Fig. 3, in which position they are entirely out of the way and will not interfere with the dropping of the lumber or boards from the log on the log-carriage onto the conveying-belts 11. When the log-carriage moves rearward or away from the observer with respect to Fig. 1 and when it has carried the log in that direction past the saw, the board cut from the log will fall onto the conveying-belts 11 and will be fed forward or toward the observer of said Fig. 1. At this time, as already stated, the bridgingarms 16 will be held in their dotted-line positions, as shown in Fig. 3. Should this movesaid deck, will cross over the said bridgingarms to the carriage, where it will be caught and held in the usual way. It will thus be seen that the log may be moved across the bridging-levers to the carriage even before the conveying-belts 11 have carried the last piece of the previously-sawed log out from under the said bridging-arms, so that no time whatever is lost and the lumber-feeding dedevices are permitted to constantly run.

It is here important to note that the bridging-levers in moving from their operative positions into their inoperative positions move in the same general direction in which the new log makes its first movement with the log-carriage. Hence even if some portion of the log or a projection thereof should catch these bridging-levers or one thereof no damage would be done, since under the yielding action permitted by the air motor or engine they would simply be forced toward their inoperative positions with an abnormally rapid movement. Statedin anotherway,theabove noted advantage is gained by arranging the bridging-levers so that they move pivotally from their projected or operative position toward the saw and from their normal orinoperative position away from the saw.

The plurality of chains which make up the conveying-belts 11 afiord an extremely efficient conveying mechanism for the lumber.

In Fig. 2 the numeral 25 indicates an ordinary combined log stop and kicker of what is known as the Kline type and which is shown as connected to and operated by the piston-rod 26 of a fluid-pressure motor 27, shown as secured to a'depending beam 28 of the floor 1. This device, however, forms no part of my present invention.

What I claim, and desire to secure by Letters Patent of the United States, is as follows:

1. In a sawmill of the character described, the combination with the log-deck and carriage, of a pair of bridging-arms pivoted for swinging movements in a horizontal plane, and means for moving the same to and from an operative position in which they bridge the space between the said deck and carriage, substantially as described.

2. In a double-cutting band-saw mill, the combination with a log-deck, saw and carriage, of a pair of bridging-levers pivoted at the delivery end of said deck for swinging movements in a horizontal plane, means for moving said levers to and from an operative position in which they bridge the space between the said deck and carriage, and a lumber-conveyer working below said bridging-levers, substantially as described.

3. In a double-cutting band-saw mill, the combination with a log-deck, saw and carriage, of a pair of bridging-levers pivoted at the delivery end of said deck for swinging movements in a horizontal plane, rests for the free ends of said bridging-arms adjacent to the said carriage, means for moving said ing-levers for bridging the space between said deck and carriage, which levers are mounted to swing or oscillate in a horizontal plane and are moved from their operative to theirinoperative positions in'the same direction in which said carriage makes its first movement after receiving a log, substantially as described.

In testimony whereofv I affix my signature in presence of two witnesses.

HERMANN G. DITTBENNER.

Witnesses:

E. H. KELIHER, F. D. lvIERCI-IANT. 

